A British Sanitary Engineer, goes on holiday with a set of plans for a new secret weapon which he has mistaken for his new plumbing invention. Everyone is hunting for him, including the Russians. The Russians find him and offer him a job in the Kremlin doing research (on plumbing he believes). He accepts, arrives in Russia and falls in love with Tania, a secret agent. And then discovers the true nature of the plans he is carrying...
George Cole
as George Archibald Potts
Oskar Homolka
as Zekov
Nadia Gray
as Tania
Wilfrid Hyde-White
as Sir Hubert Wells
Richard Wattis
as Barnes
Irene Handl
as Mrs. Tidmarsh
Christopher Lee
as Russian Agent (uncredited)
Frederick Leister
as Prime Minister
Frederick Valk
as Rakov
Geoffrey Sumner
as Pike
Ronald Adam
as Barworth Controller
Edwin Styles
as Barworth Superintendent
